Tracheal Introducer Sheath

ABSTRACT

According to the CDC, the same month (March, 2020) they declared COVD-19 a pandemic, nearly 25% of confirmed COVID-19 hospitalized patients required intubation, or ventilator use. More recently, in the US, during the summer of 2021, child intubations more than quadrupled, when the Delta variant predominated.As Omicron and additional COVID-19 variants continue to arise globally, there will be an increasing number of sudden spikes in critical illness and respiratory failure. Preparedness with efficacious airway tools that optimize success rate of intubations is critical.Without the proper tools, intubation procedures take excessive time, and can fail entirely, causing diminished central nervous system oxygenation and potentially permanent neurologic sequelae. Airway adjuncts such as the Tracheal Introducer Sheath (TIS) and Simplified Tracheal Introducer Sheath (STIS) hold immense potential to improve chances of successful intubations.The TIS is a STIS with an added articulating mechanism, but otherwise is a similar device. For the purposes of further explanation, the TIS refers to both TIS and STIS unless otherwise specified.TIS is an adjunct medical device for control and guidance of any form of tracheal introducer device through the glottic opening of a patient&#39;s airway. This facilitates endotracheal intubation by passage of the endotracheal tube.An airway introducer is placed within and controlled by the TIS, a mechanically specialized sheath, open at both ends, and covering the distal end of the introducer (where control is most relevant). The TIS acts as a relatively stiff channel, or tunnel, for the introducer to be directed through for smooth travel along courses of varied angles. The proceduralist is able to apply curvature in real-time to the TIS-introducer assemblage based on patient anatomy and other clinical factors. Without the TIS as a channel, an introducer alone can be bent at its tip, but it is limited in its ability to move along that axis as it is being proximally controlled, outside of the patient.The mechanistic basis for the sheath&#39;s guidance capability is based on composition, including, but not limited to, a hollowed shaft of polytetrafluoroethylene (PTFE), with a specific ID/OD (internal diameter/outer diameter) ratio, such that there is sufficient stiffness for the sheath to act as a guide within which the introducer can travel, whilst maintaining appropriate elasticity for malleable control.The TIS confers additional introducer controllability by minimizing introducer wobble, as introducers can consist of relatively long shaft-like devices, often nearly 60 cm.Introducer guidance by a TIS, but not the simplified version (STIS) includes a distal articulating tip mechanism, angled as needed while in the tracheal space of a patient, and controlled outside of the patient by moving the proximal sheath through a pull sheath mechanism. To recap, the Simplified Tracheal Introducer Sheath (STIS) lacks this articulating mechanism, but otherwise is a similar device.Rotatory control in the case of both the TIS and STIS is achieved by rotating the introducer which sits outside the proximal end of the sheath.A major additional benefit of utilizing a sheath with an introducer is selection of an introducer for placement into a sheath on a case-by-case basis. For example, a smaller, softer tipped introducer could be utilized with a TIS in cases where airway friability or injury is of particular concern; ie a mass with high vascularity and bleeding potential. In another example an introducer with a central canal for oxygenation can be utilized with a TIS when the decision is made to oxygenate through the introducer prior to placement of the endotracheal tube.Finally, the TIS, with its integration of an articulating mechanism utilizing a pull sheath is without costly electrical components and thus serves as a cost-effective alternative to fiberoptic intubation with a bronchoscope (often utilized among top academic hospitals), which is often cost prohibitive for many rural and community hospitals to stock. As such, the TIS may improve access of lower socioeconomic classes to important technologies in the management of respiratory failure.

This application claims priority to provisional eFiled ApplicationNumber 63283455; EFS ID 44374429; Confirmation Number 1883; Title ofInvention: Tracheal Introducer Sheath; First Named Inventor: ChristopherTaicher; Receipt Date 27 Nov. 2021.

CROSS-REFERENCE TO RELATED APPLICATIONS

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STATEMENT REGARDING FEDERALLY SPONSORED RESEARCHED OR DEVELOPMENT

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BACKGROUND OF THE INVENTION

Severe and critical cases of COVID-19 raise clinical concerns forprogression to respiratory failure and a need for airway protection withendotracheal intubation. [What is endotracheal intubation? A proceduretypically requiring utilization of a laryngoscope blade in one hand tohelp visualize the vocal cords (“cords”) and glottic opening for passage(with the opposite hand) of an endotracheal tube into the trachealspace.]

Since nearly 20% of past COVID-19 cases were considered severe orcritical, according to a large 2020 study in the Journal of the AmericanMedical Association, the U.S. healthcare system must be prepared forspikes in COVID-19 incidence and related increases in frequency ofairway failures. The pediatric COVID-19 population characteristicsunderscore this point: Among 20,714 hospitalized children andadolescents diagnosed with COVID-19, 31% experienced severe COVID-19.

There is an additional problem that proceduralists (emergency medicinephysician, anesthesiologist, ambulance personnel, etc.) face: theso-called “difficult airway”, or those that pose technical challenges.

Difficult airways represent up to nearly one-quarter of all intubationsand according to the American Journal of Respiratory and Critical CareMedicine, are due mostly to a difficulty placing the endotracheal tube.This can be for many reasons including difficulty visualizing the cordsdue to edema (a well described complication with COVID-19-associatedacute respiratory distress syndrome, or ARDS), foreign body, a malignantmass, or simply patient's baseline anatomy. The outcomes ofCOVID-19-associated ARDS patients are especially grim, with a mortalityof 45%, and thus this population deserves special attention in the U.S.research and development spaces.

Regardless of the cause, complicated intubation procedures that takeexcessive time (with multiple “passes” or attempts at passing anendotracheal tube) are associated with diminished central nervous systemoxygenation and potential neurologic disease.

As such, much effort has been put towards improving likelihood of firstattempt (“first pass”) success during expectedly and unexpectedlydifficult intubations. The most notable of airway adjuncts for thispurpose is the Bougie Device, patented in 2007 (U.S. Pat. No.US20100307489A1).

Introducers, like the Bougie Device, tend to be helpful because of theirrelatively small size and (depending on device) kinked and malleabledistal tip as compared to an endotracheal tube. Once an introducer ispassed through the cords, sometimes blindly (again, due to severepathology such as edema, or anatomy, or both), tracheal positioning ofan introducer is confirmed by feeling tracheal rings as vibratoryfeedback in the hand operating the introducer. Subsequently, anendotracheal tube is passed over the introducer, and the introducerremoved from the patient, for endotracheal tube securing and thenattachment to a mechanical ventilator.

Given strong evidence on first-attempt intubation success beingsignificantly higher when using an introducer, intubation proceduralistswill likely be continuing to utilize introducers.

The most notable problem with existing introducers, including the BougieDevice, is its limited ability to maintain desired contour and, oncethey have been placed beyond the oral cavity and oropharynx, take asharp angle around an often obstructing epiglottis to move through thecords. A kinked or angled introducer tip is extremely limited in takingsteep angles because it is pushed by the proceduralist with a forcevector driven mostly external to the patient. Sometimes theproceduralist is controlling the introducer within the patient'soropharynx, but this still is relatively external and angled away fromthe deeper glottic opening. Thus, curving the tip of an introducer thatis deep in the patient's airway confers only so much ability to take asteep angle. However limited, an operator can also move the introduceralong a curved plane to add some improved angular control.

With both the TIS and STIS, and relatively stiff sheath through which anintroducer can move allows the introducer to move along the axis createdby the sheath itself, which can be molded quickly to the desired angle,regardless of steepness, up to ninety degrees.

As mentioned, manually molding a kink of varied angles at the tip of anintroducer prior to introduction into the patient is common practice toaid its navigation towards and through the cords, however thiscorrective action has limited utility, including an inability tomanipulate the angle once placed into the patient.

The TIS solves this problem by taking on varied angles (articulatingbetween 10 and 90 degrees), in real time, controlled at the proximal endof the TIS (outside of the patient), whilst the distal introducer isplaced deeper in the airway.

While a patent pending articulating device (Total Control Introducer byThrough The Cords LLC) includes an articulating mechanism, the device isitself an introducer. Uniquely, the TIS is a sheath through which abroad range of introducers can be controlled. As such, varied introducersize, material, shape and design (ie ones with a central lumen foroxygenation or blunt-closed-end tips) can be chosen on a clinicalcase-by-case basis for utilization with a TIS. For example, a patientwith an especially friable airway can be intubated using a TIS and anespecially soft tipped introducer to avoid potentially injuring the softtissue and causing acute and chronic complications, such as bleeding andfistula creation, respectively. Any number of introducer types can bedesigned and manufactured for assembly with a TIS.

In addition to a TIS allowing for selection of varied introducer typeson a clinical case-by-case basis, it eliminates waste of existingsupplies of introducers, and supports continued, specialized andstreamlined manufacturing.

Another issue with known introducers, Bougie, Frova and others, aretheir relative unwieldy form. Given they are composed most commonly ofthin (commonly approaching 6 mm), lengthy (often between 50 and 70centimeters), PTFE, they produce a somewhat flimsy structure. This is ofparticular concern during acute and emergency settings wherein patientand environmental factors require steadied instrumentation. Introducersof this length will wobble in free space above the patient, whichtransfers to the distal introducer (inside the patient). This can becomea similarly haptic challenge at the proximal end when attempting toplace and slide a endotracheal tube over the introducer.

TIS solves the unwieldiness of most introducers by sheathing them inmaterial with relative stiffness (increased elasticity modulusthroughout), including but not limited to PTFE with a specified ID/ODratio (see below).

The invention will be more fully understood by reference to thefollowing descriptions accompanying drawings.

FIELD OF THE INVENTION

Adjunct for airway intubation involving tracheal introducers.

BRIEF SUMMARY OF THE INVENTION

The present invention is an airway adjunct that allows for ease ofpassage of an introducer through the glottic opening. The placement ofan introducer may be utilized to assist with the ultimate goal ofendotracheal intubation, or for whatever the primary goal of theproceduralist, including, but not limited to placing an introducerprimarily for emergent oxygenation through the introducer with centralcanula.

An unprecedented benefit of this invention is the ability to select anintroducer on a clinical case-by-case basis (of varied size, style,shape and design) for sheathing into the TIS. An introducer sheathed inan TIS offers the proceduralist substantial improvement in hapticcontrol, including improved maneuverability, remote distal articulatingcontrol, an improved force vector by sliding an introducer over arelatively stiff distal channel, and thus overall ease of use and safetyprofile.

This device supports manufacture of introducers by manufacturers whomaintain particular knowledge and streamlined operations of introducersof varied material, specialty and function.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)

FIG. 1 is a schematic illustration of a human airway with a trachealintroducer sheath device with introducer placed within (also referred toas ‘sheath-over-introducer assemblage’).

FIG. 2 shows the tracheal introducer sheath device.

FIG. 3 illustrates an introducer device placed within the sheath of thetracheal introducer sheath.

FIG. 4 illustrates an axial view of a TIS (but not a BTIS) from proximaland distal ends (above and below, respectively), showing vertebratedsuccession rigid annuli.

FIG. 5 is a schematic illustration of a human airway with laryngoscopeassisted insertion of a sheath-over-introducer assemblage into thetrachea.

FIG. 6 is a schematic illustration of a human airway with laryngoscopeassisted advancement of an introducer through the tracheal introducersheath device until making contact with tracheal rings.

FIG. 7 is an illustration of a human airway with correct placement of anintroducer in the trachea after a tracheal introducer sheath device hasbeen removed.

FIG. 8 is a schematic illustration of a human airway with correctplacement of an endotracheal tube over an introducer and into thetrachea.

FIG. 9 illustrates the resulting position of the endotracheal tube afterremoval of an introducer.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 2 of the drawings illustrates a preferred embodiment of theinvention which has been referred to hereinabove as a trachealintroducer sheath (TIS), since the instrument 6 is applicable toassisting passage of a tracheal introducer 10 into the airway, throughthe oropharynx 9 and past the glottis, for endotracheal intubation. Itis to be understood, however, that instrument 6 is not limited to theaforementioned uses. It may, for example, be used for sheathing anintroducer 10 of many types such as but not limited to one with acentral lumen, for emergent airway oxygenation.

Instrument 6 comprises a main portion of the body 5, connecting anopen-ended sheath (proximal opening 1 and distal opening 4) by ahollowed tube of PTFE, twelve to fifty centimeters long, with variedID/OD ratios depending on the chosen length.

As a point of clarification, the length of each individual instrument 6will generally not be modifiable. A notable functional exception wouldbe if an introducer 10 manufacturer produced an introducer 10 withmodifiable length. In this case, if the introducer 10 is placed throughthe instrument 6, length would be modifiable of thesheath-over-introducer assemblage.

For an adult instrument 6 of length between twelve and fifty centimeterslong, the instrument 6 is to have an internal diameter (ID) rangingbetween 4 mm and 7 mm with outer diameter (OD) ranging between 6 mm and11.5 mm. Tube thickness for an adult instrument 6 is to range from 0.5to 3 mm. One embodiment for an adult size instrument 6 is 20.5centimeters long with an ID of 6 mm and an OD of 8.4 mm, with a wallthickness of 1.2 mm.

For the same instrument 6 sized for children, the instrument 6 length isto range from between seven to fifteen centimeters long with IDs rangingbetween 2.5 mm and 5 mm. Outer diameters will range between 4.5 mm and 7mm. Tube thickness for a pediatric version of instrument 6 is to rangefrom 0.2 to 2 mm.

For the TIS but not the STIS, operator controlled articulation of thearticulating component 3 occurs by applying a pull force to the proximalportion 2 of the instrument 6, which transmits along an internallyinstalled vertebrate succession of rigid annuli 12 from the proximalportion 2 of the instrument 6 through the body 5 and into thearticulating component 3 of the tip and distal opening 4, allowing forproximal operating wires (illustrated in FIG. 4 ) to effect a smoothlyoperating graduated bending over a substantial length of theinstrument's 6 distal portion, without effect upon intermediate portionof the body 5 and proximal portions 2 of the sheath 6. The vertebratesuccession of annuli 12 seen in FIG. 4 is installed internally to thesmooth internal surface of the sheath, maintaining smooth passage of anintroducer. For those interested in greater detail in the constructionof a pull-sheath that maintains a uniformly diametrically dimensionedinternal hollow cavity throughout a tube within which fiber bundles areextended, allowing simultaneous proximal-to-distal control of anarticulating mechanism, see U.S. Pat. No. 3,913,568.

The articulating component 3 allows angulation 7 between five andninety-five degrees.

The size of the internal diameter of the instrument is constantthroughout each individual instrument 6 but can vary between differentinstruments 6, allowing for passage of different sized introducers 10when desired by the proceduralist.

FIG. 3 Illustrates a sheath-over-introducer assemblage, emphasizing boththe adjunct nature of the instrument 6, to be utilized with anintroducer 10, as well as the 360-degree free rotational movement of anintroducer within an instrument 6.

The first steps of operating a tracheal sheath introducer 6 areillustrated in FIG. 5 , during which a proceduralist uses either directlaryngoscopy or video-assisted laryngoscopy to insert a trachealintroducer sheath device 6 with introducer into the airway.

Once in appropriate proximity to the glottic opening, the trachealintroducer sheath device 6 is held in place, acting as a supportingvehicle through which the introducer is passed and directed towards thetracheal rings 8 (FIG. 6 ) until a vibratory sensation is felt thatreflects tracheal ring 8 resistant forces have been met. Given the needto hold the laryngoscope and the sheath instrument 6, a third persontrained in this procedure will advance the introducer 10 at theinstruction of the main operator or proceduralist (holding thelaryngoscope). Conversely, the proceduralist may ask an appropriatelytrained assistant to hold the sheath instrument 6 whilst theproceduralist advance the introducer 10.

At this point, the introducer 10 is held in place while the instrument 6can be removed (FIG. 7 ) and an endotracheal tube 11 subsequently slidover the introducer 10 as in FIG. 8 . The introducer is removed andendotracheal left in place (FIG. 9 ) for subsequent securing andmechanical ventilation.

1. Both a tracheal introducer sheath (TIS) device and simplifiedtracheal introducer sheath device (STIS) are for guiding insertion of atracheal introducer through the glottic opening of a person's airway,said sheath devices comprising: a hollowed tube of flexible materialwith (in the case of the TIS but not the STIS) internal wall fiberbundles extended from proximal to distal ends for proximal-to-distalcontrol of an articulating mechanism, through which (with either a TISor STIS) a tracheal introducer can be easily passed and manuallycontrolled.
 2. The said tube of claim 1 in which the hollowed tube ismade of polytetrafluoroethylene.
 3. The said tube of claim 1 in whichthe hollowed tube is of sufficient length to provide coverage of distalend of the said tracheal introducer whilst operator handling is over thesaid hollowed tube but not so long as to limit removal of the saidhollowed tube after introducer placement into the trachea.
 4. The saidtube of claim 1 in which the hollowed tube is a hollowed tube withinternal to external diameter ratio creating sufficiently rigid channelfor introducer to be guided along the path of the long axis of the saidhollowed tube in varied curved forms yet sufficiently flexible to allowoperator malleability and shape memory of said hollowed tube.
 5. Thesaid tube of claim 1 is with internal diameter that is sufficientlysmall to allow some contact with said tracheal introducer for vibratoryfeedback during distal contact with tracheal rings but sufficientlylarge diameter to allow smooth passage through the said hollowed tubeand sufficient stiffness through the body of said hollowed tube.
 6. Thesaid internal wall fiber bundles of claim 1 are uniformly diametricallydimensioned and internal to the internal walls of said hollowed tube andthroughout the said hollowed tube within which fiber bundles areextended, allowing simultaneous proximal-to-distal control of anarticulating mechanism facilitating guidance of said trachealintroducer.
 7. A method of guiding insertion of a tracheal introducerthrough a tracheal introducer sheath beyond the level of the vocal cordsfor subsequent placement of an endotracheal tube into the airway of aperson, the method comprising: providing a tracheal introducer sheathdevice comprising a hollowed tube; arranging the hollowed tube tocomprise polytetrafluoroethylene and to have internal to externaldiameter ratio creating sufficiently rigid channel for said trachealintroducer to be guided along the path of the long axis of the saidhollowed tube in varied curved forms yet sufficiently flexible to allowoperator malleability and shape memory of said hollowed tube, insertingthe sheath-over-tracheal introducer assemblage into the airway; guidingthe said trachea introducer into the trachea through said trachealintroducer sheath and confirmed by vibratory feedback of tracheal ringsthrough said trachea introducer and said tracheal introducer sheath intothe operator's hands; positioning the endotracheal tube over the saidtracheal introducer and subsequently removing the said trachealintroducer.
 8. The method according to claim 7 including arranging saidhollowed tube of length allowing grasping but not so long as to limittemporary holding of said tracheal introducer during removal of the saidhollowed tube after said introducer placement into the trachea.
 9. Themethod according to claim 7 including arranging said hollowed tube withinternal diameter that is sufficiently small to allow some contact alongthe hollowed tube length with said tracheal introducer for vibratoryfeedback during distal contact with tracheal rings, but sufficientlylarge diameter to allow smooth passage through the said hollowed tubeand sufficient stiffness through the body of said hollowed tube.